The present invention relates to a printed cloth on which dyes are deposited in dots and a method for the preparation thereof.
Conventionally, screen printing process and roller printing process have been applied as the method for printing cloths. However, these processes require screens and chased rolls according to the desired printing patterns. Therefore, they showed difficulties in both workability and economics when each small lots of many grades was required to be printed.
Thus, the ink jet printing process has been investigated and various patent applications have been submitted including Japanese Laid-Open Patent Publication No. 6347 of 1986, No.300377 of 1990 and No.45774 of 1991.
Japanese Laid-Open Patent Publication No.6347 of 1986 describes that a fine pattern of deep color can be attained by performing dot dyeing so that a) the average of the major axis and the minor axis of the dot is 100 to 500 xcexcm, b) the dot density is not higher than 16 dots/mm and c) the dots penetrate through the front surface to the back surface and part of the color points can be seen on the back surface of the cloth. However, by such a dyeing method, no deeper color can be attained than that attained by screen printing and no fine line of 0.3 mm or less can be attained as a printed pattern. It was also difficult to give an exact stripe pattern and a natural gradation pattern.
The object of the present invention is to provide a printed cloth in which fine line of 0.3 mm or less, an exact stripe pattern, a natural gradation pattern or the like is clearly dyed in a deep color, which could not be attained by conventional methods.
The product of the present invention is one in which a desired printed pattern is formed on a cloth by dyeing in dot a dye on it by a special ink jet process. The present invention is also characterized in that the dot dyeing is formed in a length of 0.05 to 0.3 mm to the longitudinal direction per single fiber unit constituting the cloth.
Thus, in the present invention, the dyeing unit of the dot dyeing formed is a very small line of 0.3 mm or less along the fiber to the longitudinal direction of the fiber with a thickness of the single fiber (about 0.01 to 0.1 mm). Therefore, each yarns constituting the cloth can be dyed in different colors as if they consist of different grandrelle yarns to obtain a product having fine lines, an exact stripe pattern and the like, which could not be accomplished up to now.
The printed pattern prepared by the present invention is basically formed by dot dyeing a very small line along the fiber of 0.3 mm or less to the longitudinal direction of the fiber with a thickness of the single fiber (about 0.01 to 0.1 mm). Alternatively, the dot dyeing is accomplished by each adjacent or plurality of adjacent fibers to a same color and the part in which one dot dyeing is made over the adjacent fibers such that half thicknesses of the adjacent fibers are dyed.
The product of the present invention can be prepared by a printing process according to ink jet method as described in Japanese Patent Application No.278112 of 1990, No.298399 of 1990 and No.88545 of 1991. However, it is preferred to be formed by using dyes of the three primary colors or the three primary colors and a black color as the dyes. By using them, the present invention can achieve not less than 125 combined colors per unit pattern.
Three dyes including yellow, red (magenta) and blue (cyan) are used as the dyes of the three primary colors. It is preferred to use dyes (I to IV) having a perceived chromaticity index defined in CIE 1976 (L, a, b) space on the cloth of at least in the following range respectively as these dyes and the black dye:
These dyes may also be used as a combination of at least two of each colors. The dyes of the following range can be also used in combination:
It has been found that a printed cloth of wide color range and of high clearness can be prepared particularly when seven dyes having a perceived chromaticity index defined in CIE 1976 (L, a, b) space on the cloth of at least the following range respectively are used in combination:
Generally, the color range which can be expressed by the three primary colors and the black color is within the range of the dotted line in FIG. 2A and a part of green, orange and violet can not be fully expressed in some cases. Therefore, in the case where it is required to express these colors, it is preferred to use additionally at least one selected from orange (above VI), violet (above IX) and green (above X), particularly the dyes having the following a value and b value in addition to the dyes of the three primary colors and black color:
When these dyes are additionally used, the colors in the range of the solid line of FIG. 2B can be clearly obtained.
It is preferred to pretreat the cloth before dyeing to prevent bleeding of the dye liquid. Such a treatment is preferably made by calendering the cloth and/or by giving a water repellent finish to the cloth using a water repellent or a softening and water repellent thereby acheiving a water absorption of 5 to 240 seconds measured by JIS 1096A method or a water repellency of 50 or lower measured by JIS L-1018.
Such water repellents include, for example, fluorine compounds, silicone compounds and zirconium compounds. Such softening and water repellents include, for example, octadecylethyleneurea, zirconium acetate, polyolefine compounds, wax compounds, silicone compounds and the like. Fixing agents such as alkaline substances, e.g., sodium carbonate and sodium bicarbonate, and hydrotrope agents, e.g., urea, monomethylurea, dimethylurea, thiourea, monomethylthiourea, dimethylthiourea, formamide, dimethylformamide and dimehylacetamide may be also added to them.
Such a water repellent treatment may be carried out by using at least one compound selected from the above-mentioned water repellents and the softening and water repellents in combination with a sizing agent. Such sizing agent include, for example, water-soluble cellulose derivatives such as starch, soluble starch, water-soluble starch, water-soluble starch derivatives, carboxymethylcellulose, etherified carboxymethylcellulose, hydroxyethylcellulose and methylcellulose, gums such as sodium alginate, gum arabic, locust bean gum and guar gum, water-soluble proteins such as gelatin and glue, and water-soluble synthetic high polymers such as sodium polyacrylate, polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, polyacrylamide, polyethyleneimine and quaternarized water-soluble cationic polymers. Furthermore, the bleeding of the dye liquid can be prevented by applying a breaking treatment in combination.
Particularly, it is preferred to use at least one compound selected from carboxymethylcellulose, etherified carboxymethylcellulose and sodium alginate and at least one compound selected from water-soluble acrylic resins and maleic acid resins in combination with the sizing agent mentioned above.
It is preferred that the water repellent and the softening and water repellent are applied so that they are only adhered to the outer surface of the cloth. In this case, it may be processed so that the water-absorbing agent is adhered on the back surface of the cloth where the water repellent and the softening and water repellent are not adhered.
The water-absorbing agent is not particularly restricted and, for example, a sizing agent and a water-absorbing silicone salt can be used.
Furthermore, as the method for pretreating the cloth, a method can be used in which a dye ink which can be adhered in dot during the printing is absorbed and maintained instantaneously on the surface of the cloth and a highly water-absorbent resin is adhered to prevent bleeding of the dye and color mixing. As the highly water-absorbent resins, any of the commercially available highly water-absorbent resins can be used. It is preferred to use a graft-polymerized or partly crosslinked product of water-soluble polymers such as of starch type, protein type, cellulose type or synthetic polymer type which have an ability of maintaining 10 to 1000 times amount of water based on its weight. The highly water-absorptive resin based on fibroin described in Japanese Patent Publication No. 57974 of 1983 can be used very effectively. The highly water-absorptive resin can be used together with other treating agents and particularly it is preferred to be used together with a softening and water-repellent.
As the dyes, reactive dyes, acid dyes, direct dyes, dispersion dyes, cationic dyes and fluorescent dyes may be used in accordance with the type of the fiber of the cloth to be dyed. It is preferred that the dye liquid is prepared to have a surface tension of 30 to 65 dyne/cm (particularly 40 to 50 dyne/cm) and a viscosity of 4 cps or less (particularly 1 to 2 cps) at 25xc2x0 C.
It is preferable to use the following dyes as the three primary color dyes and black dye as they give sure dye fastness after dyed. The numbers show their CI numbers.
(1) Direct dyes
C.I. Direct Yellow 28, 39, 106
C.I. Direct Red 79, 80, 83, 92
C.I. Direct Blue 71, 78, 86, 106, 189, 199, 207, 218
C.I. Direct Black 62, 113
(2) Acid dyes
C.I. Acid Yellow 17, 19, 25, 38, 42, 49, 61, 72, 116, 127, 141, 161, 207
C.I. Acid Red 19, 28, 35, 37, 51, 57, 62, 95, 111, 114, 118, 131, 134 138, 145, 149, 158, 249, 254, 266, 274, 315, 366
C.I. Acid Blue 40, 49, 62, 78, 90, 92, 112, 113, 126, 127, 129, 133, 138, 140, 182, 299, 300
C.I. Acid Black 24, 26, 107, 109, 112, 155, 234
(3) Reactive dyes
C.I. Reactive Yellow 2, 81, 95, 116, 142, 161, Orange 12
C.I. Reactive Red 4, 24, 45, 108, 218
C.I. Reactive Blue 2, 5, 15, 19, 41, 49, 72, 75, 190
C.I. Reactive Black 1, 8
(4) Dispersion dyes
C.I. Dispersion Yellow 79, 160
C.I. Dispersion Red 50, 72, 127, 146, 154
C.I. Dispersion Blue 73, 142, 198, 224
C.I. Dispersion Black 1
Furthermore, in the present invention, it is preferred to use the dyes after removing inorganic salts, dispersing agents and solubilizers from them so that the dye liquid of very fine drops can be stably delivered in order to deposit the dye liquid on the cloth as a very small dots which can dye each single fibers in different colors. For example, it is preferable to use a water-soluble dye in which the contents of sodium, potassium, phosphorous and copper are respectively not higher than 0.01% and the contents of the anionic surface active agent and the nonionic surface active agent are respectively not higher than 0.015%. Particularly, when the contents of the mono- and divalent metal ions are controlled to be not higher than 10 ppm, it is preferred to use a water-soluble dye having a water solubility of not higher than 50 g/l at 20xc2x0 C.
The following dyes can be exemplified as such water-soluble dyes. The numbers show their CI numbers.
{circle around (1)} Direct dyes
C.I. Direct Yellow 28, 106
C.I. Direct Red 80, 83, 89
C.I. Direct Blue 80, 86, 106, 189, 199, 207
{circle around (2)} Acid dyes
C.I. Acid Yellow 7, 38, 49, 72, 79, 141, 169, 219, 246
C.I. Acid Red 52, 114, 138, 249, 254, 260, 274, 361
C.I. Acid Blue 7, 9, 62, 90, 112, 113, 185, 225
C.I. Acid Black 26, 52, 109, 110
{circle around (3)} Reactive dyes
C.I. Reactive Yellow 13, 14, 75, 76, 77, 79, 115
C.I. Reactive Red 22, 23, 108, 109, 110, 111, 112, 113, 114
C.I. Reactive Blue 14, 19, 21, 27, 28, 100, 101, 148
C.I. Reactive Black 1, 5, 8
These water-soluble dyes are dissolved in water together with a dryness inhibitor to prepare a printing ink for ink jet. It is preferred to use glycols such as ethylene glycol, diethylene glycol, triethylene glycol, thiodiethylene glycol, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether and polyethylene glycol dimethyl ether and urea and the like as the dryness inhibitors in amounts of 100 to 300 g/l.
When a reactive dye is used, it is preferable to be used as an aqueous ink containing an alkyl ether derivative of a polyhydric alcohol prepared by etherifying the primary and secondary alcohol groups in the polyhydric alcohol. In general, it is made to be a printing ink for ink jet consisting of 1 to 20 weight % of a reactive dye, 1 to 40 weight % of an alkyl ether derivative of a polyhydric alcohol mentioned above and 40 to 98 weight % of water. Known hydrotrope agents and surface active agents may be added to the printing ink.
The orange, violet, green and navy blue dyes additively used together with the three primary color dyes include the followings. The numbers show their CI numbers.
{circle around (1)} Direct dyes
C.I. Direct Orange: 26, 29, 34, 39, 102, 118
C.I. Direct Violet: 9, 35, 47, 51, 66, 93, 95
C.I. Direct Green: 26, 59, 67
C.I. Direct Navy blue: blue 251, 248
{circle around (2)} Acid dyes
C.I. Acid Orange: 7, 10, 56, 94, 142
C.I. Acid Violet: 19, 48, 49, 129
C.I. Acid Green: 5, 6, 12, 15, 19, 21
C.I. Acid Navy blue: blue 92, 120
{circle around (3)} Reactive dyes
C.I. Reactive Orange: 1, 4, 5, 7, 12, 14, 15, 16, 20, 29, 30
C.I. Reactive Violet: 1, 2, 4, 5, 6, 8, 9, 22, 34, 36
C.I. Reactive Green: 5, 6, 12, 15, 19, 21
C.I. Reactive Navy blue: blue 147, Black 39
{circle around (4)} Dispersion dyes
C.I. Dispersion Orange: 1, 3, 11, 13, 20, 25, 29, 30, 31, 32, 47, 55, 66
C.I. Dispersion Violet: 1, 4, 8, 23, 26, 28, 31, 33, 35, 38, 48, 56
C.I. Dispersion Green: 6, 9
C.I. Dispersion Navy blue: blue 146, 186
The printed cloth of the present invention is prepared by a procedure in which a cloth is optionally pretreated as mentioned above and then, or directly with no such pretreatment, a printing ink is sprayed on it to fix a desired printing pattern on it by an ink jet printing apparatus. Such printing apparatus include, for example, an apparatus including an ink jet recording head as described in Japanese patent Application No. 88545 of 1991. However, in order to make a fine dot printing desired by the present invention possible, it is preferred that a dye spraying apparatus, which has nozzles of not less than 80 dots/cm (200 dpi), particularly not less than 120 dots/cm (300 dpi), for three primary colors, is controlled based on the image signal to print a desired image with the use of the three primary color dyes.
The ink jet methods include, for example, a bubble jet method in which a heating resistor element is buried in a nozzle and an ink is boiled by its heat and the ink is delivered by the pressure of the bubbles, a pulse jet method in which an electric signal is applied on a piezoelectric element to deform it and the ink particles are blown by the excited volume change of the ink chamber, and an electric charge control method in which an ink is continuously pressure-sprayed from a nozzle vibrating by ultrasonic wave to particulate and the particles are controlled by the charge level and deviated by being passed through a definite electric field to be divided into recording particles and nonrecording particles.
Although the dyeing is limited to 24 colors in the usual screen printing, unlimited colors can be easily realized in the present invention only by using the three primary colors or the three primary colors and black color or by adding a small number of dyes such as orange, violet, green and navy blue to them. In addition, the dyeing can be carried out in dots for each single fiber unit of the yarn constituting the cloth. The dot length is as fine as 0.3 mm or less to the longitudinal direction of the filament and therefore a product of highly natural appearance and deep color can be prepared as if it is prepared by using yarns made by twisting fibers dyed in band each other (that is grandrelle yarn) to express a fine printed pattern. As the dye is clearly deposited on the front surface of the cloth with no penetration to the back surface, a deep color dyeing of high quality can be obtained.
Therefore, according to the present invention, as fine a line as 0.3 mm or less which could not be realized by a conventional method can be expressed stably in high quality as a printed pattern and an exact stripe pattern can be also given. Furthermore, a variety of colors can be reproduced elaborately to achieve the same printing results as the original picture and thus printed patterns of gradated tone and brush touch can be prepared in very high quality.
According to the present invention, a colored resist style product can be prepared by a procedure in which a dye ink containing a dye not decomposed by a reducing agent is applied on a cloth by ink jet method to form a printed pattern and then a reducing agent is applied on the printed pattern and the cloth is dyed with a reductively decolorizable dye.
Furthermore, a printed product of pepper-and-salt tone can be prepared by a procedure in which an original image of design is converted to a digital image data by an image input device and said image data is color separated by a color conversion device and then an ink jet device is controlled based on said separated image signals and random number signals to print the pattern on a cloth.
Although the method for the preparation of the original picture of repeated pattern in the printing according to the present invention is not particularly restricted, the preparation of an original picture can be made easily when a picture prepared by a procedure in which, when a pattern is drawn on the surface of a right-angled tetragon ABCD and the points internally dividing respectively a pair of the opposite sides AB and CD into a defined ratio m:n are defined to be E and F, said pattern is drawn so that it matches within an error of 0.3 mm or less on the segment BE and the segment DF or the segment AE and the segment CF, in both case that the segment BE and the segment DF are matched or that the segment AE and the segment CF are matched by rounding the tetragon into a cylinder so that the back surface of the tetragon ABCD comes inside is used as the original picture. In addition, a repeated pattern of high degree of perfection suitable for digital processing by a computer can be obtained.
In the present invention, the cloths include woven fabrics, knitted fabrics and nonwoven fabrics. The fibers constituting them may be natural fibers such as cotton, flax, wool and silk or synthetic fibers such as rayon, acetate, triacetate, Nylon, polyester and acrylic. They may be also their mixed fibers or union clothes.
When a cloth consisting of short fibers is used, friction marks tend to be formed by the contact of the ink jet nozzle with the fluff of the cloth. To prevent them and thus to obtain a fine image, it is preferred that the length of the fluff on the surface of the cloth is not more than 0.9 mm, the density of the fluff of 0.5 to 0.9 mm long is 15 fluffs/10 cm2 or less and the density of the fluff of 0.5 mm long or shorter is 30 fluffs/10 cm2 or less.
In order to satisfy such conditions, it is preferred to carry out a treatment with a fluff binding agent, an enzyme reduction treatment, double singeing treatment both on the raw cloth and on the scoured cloth, and shearing treatment after the preparations such as raw cloth singeing and scouring.
The fluff binding agents include, for example, water-soluble resins such as water-soluble polyester resin, polyvinyl alcohol, polyacrylic acid, casein, gelatin and thickner for printing, and emulsion resins such as hydrophilic polyester resin, vinyl compound polymers (polyvinyl acetate, polyvinyl acrylate resin and polyvinyl methyl resin).
For the above enzyme reduction, cellulose-decomposing enzymes such as cellulase and proteolytic enzymes such as protease can be used.
The singeing is carried out by a gas burner or by an electric heater. For example, the above-mentioned length of the fluff and the fluff density can be attained by a double singeing treatment both on the raw cloth and on the scoured cloth. A shearing may be carried out in place of the second singeing.